Glycolaldehyde, an Advanced Glycation End Products Precursor, Induces Apoptosis via ROS-Mediated Mitochondrial Dysfunction in Renal Mesangial Cells

Uncovering chemical profiles, biological potentials, and protection effect against ECM destruction in H2 O2 -treated HDF cells of the extracts of Stachys tundjeliensis

The genus Stachys L., one of the largest genera of the Lamiaceae family, is highly represented in Turkey. This study was conducted to determine the bio-pharmaceutical potential and phenolic contents of six different extracts from aerial parts of Stachys tundjeliensis. The obtained results showed that the ethanol extract exhibited the highest antioxidant activity in the antioxidant assays. Meanwhile, the ethanol extract displayed strong inhibitory activity against α-tyrosinase, the dichloromethane extract exhibited potent inhibition against butyrylcholinesterase, and the n-hexane extract against α-amylase. Based on ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry analysis, more than 90 secondary metabolites, including hydroxybenzoic acid, hydroxycinnamic acid, and their glycosides, acylquinic acids, phenylethanoid glycosides, and various flavonoids were identified or tentatively annotated in the studied S. tundjeliensis extracts. It was observed that the application of S. tundjeliensis eliminated H2 O2 -induced oxidative stress. It was determined that protein levels of phospho-nuclear factor kappa B (NF-κB), receptor for advanced glycation endproducts, and activator protein-1, which are activated in the nucleus, decreased, and the synthesis of matrix metalloproteinase (MMP)-2 and MMP-9 also decreased to basal levels. Overall, these findings suggest that S. tundjeliensis contains diverse bioactive compounds for the development of nutraceuticals or functional foods with potent biological properties.

Organosulfurs, S-allyl cysteine and N-acetyl cysteine sequester di-carbonyls and reduces carbonyl stress in HT22 cells

Diabetes, characterized by high blood glucose level, is a progressive metabolic disease that leads to serious health complications. One of the major pathological consequences associated with diabetes is the accumulation of highly reactive carbonyl compounds called advanced glycation end products (AGEs). Most of the AGEs are dicarbonyls and have the potential to covalently modify proteins especially at the lysine residues in a non-enzymatic fashion (a process termed as glycation) resulting in the functional impairment and/or toxic gain in function. Therefore, non-toxic small molecules that can inhibit glycation are of interest for the therapeutic intervention of diabetes. In the present communication, we have investigated the effect of organosulfurs (S-allyl cysteine, SAC and N-acetyl cysteine, NAC) that are major principal components of Allium sativa against the glycation of different proteins. We discovered that both SAC and NAC are potent anti-glycating agents. We also found that both SAC and NAC reduce ROS level and inhibit apoptosis caused by protein glycation.

A Role for Advanced Glycation End Products in Molecular Ageing

Ageing is a composite process that involves numerous changes at the cellular, tissue, organ and whole-body levels. These changes result in decreased functioning of the organism and the development of certain conditions, which ultimately lead to an increased risk of death. Advanced glycation end products (AGEs) are a family of compounds with a diverse chemical nature. They are the products of non-enzymatic reactions between reducing sugars and proteins, lipids or nucleic acids and are synthesised in high amounts in both physiological and pathological conditions. Accumulation of these molecules increases the level of damage to tissue/organs structures (immune elements, connective tissue, brain, pancreatic beta cells, nephrons, and muscles), which consequently triggers the development of age-related diseases, such as diabetes mellitus, neurodegeneration, and cardiovascular and kidney disorders. Irrespective of the role of AGEs in the initiation or progression of chronic disorders, a reduction in their levels would certainly provide health benefits. In this review, we provide an overview of the role of AGEs in these areas. Moreover, we provide examples of lifestyle interventions, such as caloric restriction or physical activities, that may modulate AGE formation and accumulation and help to promote healthy ageing.

Diabetic vascular diseases: molecular mechanisms and therapeutic strategies

Vascular complications of diabetes pose a severe threat to human health. Prevention and treatment protocols based on a single vascular complication are no longer suitable for the long-term management of patients with diabetes. Diabetic panvascular disease (DPD) is a clinical syndrome in which vessels of various sizes, including macrovessels and microvessels in the cardiac, cerebral, renal, ophthalmic, and peripheral systems of patients with diabetes, develop atherosclerosis as a common pathology. Pathological manifestations of DPDs usually manifest macrovascular atherosclerosis, as well as microvascular endothelial function impairment, basement membrane thickening, and microthrombosis. Cardiac, cerebral, and peripheral microangiopathy coexist with microangiopathy, while renal and retinal are predominantly microangiopathic. The following associations exist between DPDs: numerous similar molecular mechanisms, and risk-predictive relationships between diseases. Aggressive glycemic control combined with early comprehensive vascular intervention is the key to prevention and treatment. In addition to the widely recommended metformin, glucagon-like peptide-1 agonist, and sodium-glucose cotransporter-2 inhibitors, for the latest molecular mechanisms, aldose reductase inhibitors, peroxisome proliferator-activated receptor-γ agonizts, glucokinases agonizts, mitochondrial energy modulators, etc. are under active development. DPDs are proposed for patients to obtain more systematic clinical care requires a comprehensive diabetes care center focusing on panvascular diseases. This would leverage the advantages of a cross-disciplinary approach to achieve better integration of the pathogenesis and therapeutic evidence. Such a strategy would confer more clinical benefits to patients and promote the comprehensive development of DPD as a discipline.

Structure‒function‒pathogenicity analysis of C-terminal myocilin missense variants based on experiments and 3D models

MYOC is a common pathogenic gene for primary open-angle glaucoma and encodes the protein named myocilin. Multiple MYOC variations have been found, with different clinical significance. However, the pathogenesis of glaucoma induced by MYOC mutations has not been fully clarified. Here, we analyze the molecular and cellular biological differences caused by multiple variant myocilins, including protein secretion characteristics, structural changes, subcellular localization, cellular autophagic activity and oxidative stress. Denaturing and nondenaturing electrophoresis showed myocilin to be a secreted protein with the tendency to self-oligomerize. The full-length myocilin and its C-terminal cleavage fragment are secreted. Secretion analysis of 23 variant myocilins indicated that secretion defects are closely related to the pathogenicity of MYOC variants. Structural analysis showed that the alteration of steric clash is associated with the secretion characteristics and pathogenicity of myocilin variants. Immunocytochemistry results demonstrated that mutated myocilins are retained in the endoplasmic reticulum and disrupt autophagy. MTT assay, MitoTracker staining, and DCFH-DA staining showed increased oxidative injury in cells expressing MYOC mutants. Taken together, MYOC mutations are able to induce cell dysfunction via secretion defects and intracellular accumulation resulting from steric clash alterations.

N-Acetylcysteine, an ROS Inhibitor, Alleviates the Pathophysiology of Hyperthyroidism-Induced Cardiomyopathy via the ROS/Ca2+ Pathway

Hyperthyroidism is common and can induce cardiomyopathy, but there is no effective therapeutic strategy. The purpose of this study was to investigate the molecular mechanism of hyperthyroidism-induced cardiomyopathy (HTC) and the effect of N-acetylcysteine (NAC), an ROS inhibitor, on the pathophysiology of HTC in vivo and in vitro. Compared with those in the control groups in vivo and in vitro, TT3 and TT4 were significantly increased, the structure of myocardial cells was enlarged and disordered, and interstitial fibrosis and the apoptosis of myocardial cells were markedly increased in the L-Thy group. The ROS and inflammatory response were increased in the hyperthyroidism group. In the NAC group, the contents of TT3 and TT4 were decreased, the myocardial cell structure was slightly disturbed, fibrosis and apoptosis were significantly reduced, and the ROS level and inflammatory response were significantly reduced. Interestingly, L-Thy decreased the viability of fibroblasts and H9c2 cells, suggesting that L-Thy-induced fibrosis was not caused by the proliferation of fibroblasts. The molecular mechanism of HTC could be explained by the fact that L-Thy could cause cardiac hypertrophy, inflammation, and fibrosis by regulating the Ca2+/calpain/Rcan1-dependent signalling pathway, the Ca2+/Rcan1/NF-κB/p65-dependent signalling pathway, and the Ca2+/ROS/Bcl-2/caspase-3-dependent signalling pathway. In conclusion, NAC can alleviate the pathophysiology of hyperthyroidism-induced cardiomyopathy, probably by regulating the ROS/Ca2+-dependent pathway.